• Title, Summary, Keyword: global stability

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The Digital Cold War Argument and the Internet Governance (디지털 냉전론과 인터넷 거버넌스)

  • Kim, Jae Yeon
    • Review of Korean Society for Internet Information
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    • v.14 no.3
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    • pp.35-51
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    • 2013
  • The Digital Cold War argument has become one of the heatedly discussed foreign policy agendas in the U.S. Considering the authority and power of the U.S. government and Internet companies in the cyberspace, this shift is not negligible in understanding not only the changes in the U.S. foreign and military policies but also that in the operations of the global Internet governance. Given these circumstances, I seek to explain the origins of and test the theoretical validity of the Digital Cold War argument. In particular, I analyze how the political concerns of the Chinese authorities shaped the characteristics of their control of the domestic Internet and their approach to the global Internet governance. The findings indicate that the Chinese way of the Internet governance is more concerned of their domestic political stability than overthrowing the current Internet governance regime, which many supporters of the Digital Cold War argument cited as the key evidence of such political contentions. Though the Digital Cold War argument is theoretically unwarranted, its growing popularity and the historical lessons of the Cold War have broad implications to the understanding of the impacts of the great power rivalries on the future Internet governance.

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Global Periodic Solutions in a Delayed Predator-Prey System with Holling II Functional Response

  • Jiang, Zhichao;Wang, Hongtao;Wang, Hongmei
    • Kyungpook Mathematical Journal
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    • v.50 no.2
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    • pp.255-266
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    • 2010
  • We consider a delayed predator-prey system with Holling II functional response. Firstly, the paper considers the stability and local Hopf bifurcation for a delayed prey-predator model using the basic theorem on zeros of general transcendental function, which was established by Cook etc.. Secondly, special attention is paid to the global existence of periodic solutions bifurcating from Hopf bifurcations. By using a global Hopf bifurcation result due to Wu, we show that the local Hopf bifurcation implies the global Hopf bifurcation after the second critical value of delay. Finally, several numerical simulations supporting the theoretical analysis are given.

Position control of robots with uncertain parameters using output-feedback controller (출력제어기를 이용한 불학실 파라미터를 갖는 로봇의 위치제어)

  • ;;Ailon, Amit
    • 제어로봇시스템학회:학술대회논문집
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    • pp.472-475
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    • 1997
  • The principle objective of this paper is to explain and demonstrate the advantage of the output-feedback controller proposed by Ailon in [61 by using simulation and experimental results. Namely, the goal of this study is to design and implement a real-time controller for set-point regulation of a one-link rigid robot manipulator with unknown parameters using only position measurement. For implementation a direct drive one-link rigid robot manipulator is constructed and a TMS320C40 DSP systems board is used in implementing real-time control algorithm.

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GLOBAL SOLUTIONS OF THE EXPONENTIAL WAVE EQUATION WITH SMALL INITIAL DATA

  • Huh, Hyungjin
    • Bulletin of the Korean Mathematical Society
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    • v.50 no.3
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    • pp.811-821
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    • 2013
  • We study the initial value problem of the exponential wave equation in $\math{R}^{n+1}$ for small initial data. We shows, in the case of $n=1$, the global existence of solution by applying the formulation of first order quasilinear hyperbolic system which is weakly linearly degenerate. When $n{\geq}2$, a vector field method is applied to show the stability of a trivial solution ${\phi}=0$.

ON THE RECURSIVE SEQUENCE $x_{n+1}=\frac{a+bx_{n-1}}{A+Bx^k_n}$

  • Ahmed, A. M.;El-Owaidy, H. M.;Hamza, Alaa E.;Youssef, A. M.
    • Journal of applied mathematics & informatics
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    • v.27 no.1_2
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    • pp.275-289
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    • 2009
  • In this paper, we investigate the global behavior of the difference equation $x_{n+1}\;=\;\frac{a+bx_{n-1}}{A+Bx^k_n}$, n=0,1,..., where a,b,$B\;{\in}\;[0,\infty)$ and A, $k\;{\in}\;(0,\infty)$ with non-negative initial conditions.

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GLOBAL EXISTENCE AND STABILITY FOR EULER-BERNOULLI BEAM EQUATION WITH MEMORY CONDITION AT THE BOUNDARY

  • Park, Jong-Yeoul;Kim, Joung-Ae
    • Journal of the Korean Mathematical Society
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    • v.42 no.6
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    • pp.1137-1152
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    • 2005
  • In this article we prove the existence of the solution to the mixed problem for Euler-Bernoulli beam equation with memory condition at the boundary and we study the asymptotic behavior of the corresponding solutions. We proved that the energy decay with the same rate of decay of the relaxation function, that is, the energy decays exponentially when the relaxation function decay exponentially and polynomially when the relaxation function decay polynomially.

GLOBAL EXISTENCE AND STABILITY OF A KORTEWEG-DE VRIES EQUATION IN NONCYLINDRICAL DOMAIN

  • Ha, Tae Gab
    • Communications of the Korean Mathematical Society
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    • v.34 no.2
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    • pp.565-572
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    • 2019
  • In this paper, we consider a Korteweg-de Vries equation in noncylindrical domain. This work is devoted to prove existence and uniqueness of global solutions employing Faedo-Galerkin's approximation and transformation of the noncylindrical domain with moving boundary into cylindrical one. Moreover, we estimate the exponential decay of solutions in the asymptotically cylindrical domain.

An optimum design of on-bottom stability of offshore pipelines on soft clay

  • Yu, Su Young;Choi, Han Suk;Lee, Seung Keon;Do, Chang Ho;Kim, Do Kyun
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.5 no.4
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    • pp.598-613
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    • 2013
  • This paper deals with the dynamic effect of pipeline installation and embedment for the on-bottom stability design of offshore pipelines on soft clay. On-bottom stability analysis of offshore pipelines on soft clay by DNV-RP-F109 (DNV, 2010) results in very unreasonable pipe embedment and concrete coating thickness. Thus, a new procedure of the on-bottom stability analysis was established considering dynamic effects of pipeline installation and pipe-soil interaction at touchdown point (TDP). This analysis procedure is composed of three steps: global pipeline installation analysis, local analysis at TDP, modified on-bottom stability analysis using DNV-RP-F109. Data obtained from the dynamic pipeline installation analysis were utilized for the finite element analysis (FEA) of the pipeline embedment using the non-linear soil property. From the analysis results of the proposed procedure, an optimum design of on-bottom stability of offshore pipeline on soft clay can be achieved. This procedure and result will be useful to assess the on-bottom stability analysis of offshore pipelines on soft clay. The analysis results were justified by an offshore field inspection.

Case study on stability performance of asymmetric steel arch bridge with inclined arch ribs

  • Hu, Xinke;Xie, Xu;Tang, Zhanzhan;Shen, Yonggang;Wu, Pu;Song, Lianfeng
    • Steel and Composite Structures
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    • v.18 no.1
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    • pp.273-288
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    • 2015
  • As one of the most common failure types of arch bridges, stability is one of the critical aspects for the design of arch bridges. Using 3D finite element model in ABAQUS, this paper has studied the stability performance of an arch bridge with inclined arch ribs and hangers, and the analysis also took the effects of geometrical and material nonlinearity into account. The impact of local buckling and residual stress of steel plates on global stability and the applicability of fiber model in stability analysis for steel arch bridges were also investigated. The results demonstrate an excellent stability of the arch bridge because of the transverse constraint provided by transversely-inclined hangers. The distortion of cross section, local buckling and residual stress of ribs has an insignificant effect on the stability of the structure, and the accurate ultimate strength may be obtained from a fiber model analysis. This study also shows that the yielding of the arch ribs has a significant impact on the ultimate capacity of the structure, and the bearing capacity may also be approximately estimated by the initial yield strength of the arch rib.

Did Fiscal Stimulus Lift Developing Asia Out of the Global Crisis? An Empirical Investigation

  • Hur, Seok-Kyun;Park, Donghyun
    • East Asian Economic Review
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    • v.22 no.1
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    • pp.55-73
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    • 2018
  • The substantial slowdown of economic growth since the global financial crisis of 2008-2009 is rekindling debate on whether developing Asia should use fiscal expansion to boost aggregate demand. A key factor in the debate is the effectiveness of countercyclical fiscal policy in the region. The global crisis, as well as the fiscal stimulus packages implemented by developing Asian countries at that time, give some clues to this important issue. The region weathered the global crisis well and experienced a robust V-shaped recovery. According to conventional wisdom, the fiscal stimulus packages put in place by Asian governments played a key role in the region's recovery. The central objective of this paper is to empirically test this wisdom by using cross-country panel data. Our main finding is that the stimulus has had a limited but positive impact on developing Asia's output during the global crisis. This lends some support to the notion that countercyclical fiscal policy can help the region cope with severe external shocks. The broader, more fundamental implication for regional policymakers is that the region's long-standing commitment to fiscal discipline can yield significant benefits beyond macroeconomic stability. An important consequence of this commitment - relatively healthy fiscal balance sheets - enabled the region's governments to quickly and decisively embark upon fiscal stimulus programs.